Threaded rings of this type are disclosed in DE Patent Application 1 675 685, for example, are commercially available and are applied in various areas of mechanical engineering. The body component forming the plane surface serves as a high-precision nut seated on the external threading of a shaft or spindle. The nut axial position along the longitudinal axis of the threaded ring can be determined with high accuracy by the second body component used as the retaining ring. The threaded flank clearance present between external threading and internal threading is eliminated in that the width of the gap between the two body components is modified by the actuating mechanism. Such modification is made possible by the elastic flexibility of the wall component forming the body components.
The actuating mechanism can be set screws permitting reciprocal tightening of the set collar and the retaining ring. The set collar may function as an adjusting nut with a plane surface forming a contact surface for positioning of roller bearings on shafts, or can be used as a precisely positioned shaft collar or the like.
In the described threaded ring, the gap between the body components is formed by two gap segments offset from each other in the axial direction. One segment extends from the threaded bore to the vicinity of the circumference of the threaded ring. The other segment extends radially inward from the circumferential surface to the vicinity of the threaded bore. Between the two gap segments, an elastically flexible wall component connects the two body components and has a wall thickness selected such that this wall component is elastically flexible. The geometry of the gap may then be adjusted by the set screws serving as an actuating mechanism. The threaded flank clearance is eliminated. The locking effect desired is achieved by tensioning the two body components. The relatively high production cost is a disadvantage of this threaded ring.
EP 0 956 768 A1 discloses another generic threaded ring made as a precision tensioning nut. This precision tensioning nut has a solid nut block having an internal threading, an end face machined flat and aligned at a right angle to the axis of the thread, and a circumferential surface. Individual clamping elements each form a radially extending segmented sector from a part of the nut block. The clamping elements, for the purpose of axial locking by a clamping screw operable parallel with the axis, may be elastically inclined. The clamping elements moreover form at most 50% of the component such that in axial locking on the tensioning side at most 50% of the circumference of the thread in the form originally produced is changed. Distortion of the plane surface and loosening by insufficient locking are thus avoided. This solution compared to the initially mentioned solution in the prior art has only one open gap segment and not two. The gap segment is also closed to the outside so that no foreign substances are able to penetrate from the outside into the gap area. The production effort and the costs are thus reduced accordingly. Only the production of the segmented clamping element is in turn associated with increased production effort. Achieving a uniform application of the clamping force is likewise made difficult as a result of the segmented configuration of the clamping elements.
DE-A-102 52 780 A1 (corresponding to U.S. Pat. No. 7,182,564) discloses another threaded ring. A second body component used as the retaining ring forms an elastically flexible wall component having a circumferential area which, compared to the first body component, is reduced to an outside diameter situated over a smaller radius than the end of the gap situated radially to the outside. The circumferential area of the second body component which has been reduced in diameter ends at an axial distance from the gap defining the extension of the flexible wall component in the axial direction.
Instead of the complex production of two gap sections, in this disclosed solution with the formation of the flexible wall component, only the configuration of an integral gap as an internal recess and the external machining of the second body component are necessary to reduce its outside diameter in areas. This reduction can be effected by simple machining.
Furthermore, in the disclosed solutions, after fixing the set collar on the assignable threaded piece and after subsequent tightening of the retaining ring, plastic deformations may unintentionally occur along the threadings. This deformation leads to the threaded ring becoming unusable. The threaded ring then possibly can no longer be removed from the clamping thread. Basically, this problem can be prevented by torque wrenches with a definable locking torque. In practical applications for the threaded ring, however, often in the absence of a suitable torque wrench, this measure is ignored and the threaded ring is fixed with conventional tools.